This invention relates to control of nitrosamine formation in nitrite cured meat.
Cured meat products have been prepared for many years by treatment of fresh meat with an alkali metal nitrite-containing composition or with a composition containing a mixture of alkali metal nitrite and an alkali metal nitrate. Sodium chloride is generally present in the curing mixture and other materials such as sugar may also be present. Spices may be added. Ascorbic acid, isoascorbic acid (sometimes called erythorbic acid) or salts of ascorbic acid or isoascorbic acid are sometimes used to accelerate the formation of cured meat pigments.
The conventional alkali metal nitrite or nitrate-nitrite containing curing mixtures provide quite satisfactory cures insofar as cured-meat preservation, flavor, and development of the pink to red color characteristic of cured meats are concerned. Nitrates were at one time used alone and then one had to depend on bacterial action for their conversion to nitrites during the curing process. No practical substitute for the nitrite ion in the curing process has yet been discovered.
Unfortunately, minute amounts of undesirable nitrosamines may occur in meats, particularly bacon, which have been cured with the conventional nitrite curing mixtures, and which have been cooked by methods in which the fats reach relatively high temperatures. For example, N-nitrosopyrrolidine and dimethylnitrosamine are found on frying bacon, the cook-out fat containing the largest proportion of these volatile nitrosamines with N-nitrosopyrrolidine being present in the greater amount. These nitrosamines are not found in the cured raw meats. Apparently, the temperature attained by the fats in frying or equivalent cooking processes, such as broiling, grilling, microwave heating, etc., facilitates the reaction of alkali metal nitrites and amines of the meat to form nitrosamines. Since N-nitrosopyrrolidine and dimethylnitrosamine have been found to be carcinogenic in tests on experimental animals, they are regarded as a potential hazard in human food products. It is desirable, therefore, to reduce, eliminate or prevent the formation of these substances in cooked meat products. It is disclosed in the afore-mentioned application Ser. No. 632,793 that 1,2-dihydro-6-alkoxyquinolines, e.g. ethoxyquin, a known food antioxidant, are useful for this purpose. It is further disclosed in the aforementioned application Ser. No. 643,558 that 1,2,3,4-tetrahydro-6-alkoxyquinolines, e.g. dihydroethoxyquin, are also useful for this purpose.